Iron bending machine



Feb. 11, 1947. H ss 'gLD IRON BENDING MACHINE Filed Dec. 20, 1943 my 2 in v w Patented Feb. 11, 1947 snare 8 Qlaims.

My present invention relates to improvements in iron bending machines of the type disclosed and broadly claimed in my United States Letters Patent Number 1,832,210, issued November 17, 1931, and entitled Die for bending angle bars.

The machine disclosed in the above identified patent is designed for use in bending angle bars, while cold, about an axis perpendicular to one flange of the angle bar and at one side thereof and with the outer edge of said flange on the concave side of the bend.

It is well known that in bending an angle bar, as heretofore stated, the upsetting of certain parts of the metal and the stretching of other parts thereof produces a stress in the bar that causes the bar to twist or distort away from its original plane and also to distort the bar from its normal angle shape to an acute angle shape.

The objects of this invention are: first, to simultaneously bend two angle bars so arranged in a bending machine that the bending thereof will generate opposing pressure that will counteract the stresses heretofore mentioned so that said bars are each bent in a perfect plane and without distorting their right angle shape; second, to provide novel stop and bending blocks; and third, to provide stop and bending blocks that are selfadjusting to the flanges of angle bars of a given width that vary in the production thereof.

Other objects of the invention will be pparent from the following description, reference being had to the accompanying drawing.

To the above end, generally stated, the invention consists of the novel devices and combination of devices hereinafter describedand defined in the claims.

In the accompanying drawing, which illustrates the invention, like characters indicate like parts throughout the several views.

Referring to the drawing:

Fig. 1 is a fragmentary plan View of the bending machine, some parts being shown in horizontal section;

Fig. 2 is a detail view principally in section taken on the irregular line 22 of Fig. 1;

Fig. 3 is a plan View of the upper radius block removed from the machine;

Fig. 4 is a side elevation of the bending block, with the angle bars sectioned on the line l& of Fig. 1;

Fig. 5 is a face View of the bending block shown in Fig. 4;

Fig. 6 is a sectional view taken on the line t-G of Fig. 7; and

Fig. 7 is a fragmentary view partly in plan and partly in section taken on the line ll of Fig. 6.

The improved bending machine includes a stationary main frame 8 and a swinging frame 9 attached to said main frame by a pivot pin it for horizontal swinging movement. Said main frame 8- is rigidly secured to a bench or other support, not shown, by nut-equipped bolts 5 l. Each frame 8 and 3 includes a pair of vertically spaced flat bars l2 and i3, respectively. The inner end portions of the bars id of the swinging frame 9 are interposed between the adjacent ends of the bars 32 of the main frame and in close working fit therewith. The pivot pin ll] extends through aligned holes in the bars l2 and 53. A hand lever Hi, only fragmentarily shown, is secured in the outer end portion of the swinging frame 9 for operating the same.

A master die I5 is interposed between the bars E3 of the swinging frame and pivotally secured to the two frames 8 and 9 by the pivot iii. This master die 55 has in its face a pair of forwardly projecting laterally spaced members it spaced equidistant on each side of the pivot pin til. Each member it has in its outer end portion a V- no-tch ll that affords upper and lower converging Wedge-acting surfaces It.

Co-operating with the master die it is a pair of vertically spaced coincident radius blocks i8. These radius blocks l9 extend into the notches ll of the master die members l6 and have, in their opposite sides 26, notches 25 into which said members project. The bottoms 22 of the notches 2! are on the same bevel as the wedge-acting surfaces i8 and have sliding contact'therewith. Obviously, inward movement of the radius blocks is into the notches ll will move said radius blocks toward each other.

The improved bending machine is designed to simultaneously bend two angle bars 0:. These angle bars :0 are placed, the one upon the other, with their vertically disposed flanges in opposing arrangement to the bending surfaces 23 of the radius blocks l9 and with their horizontally disposed fianges extending between said radius blocks.

A stop block 2% on the main frame 8 is provided for holding the angle bars as against the radius blocks i9 and a bending block 25 is mounted on the swinging frame t. These two blocks 24 and 25 are identical, the one with the other. The stop block 24 extends between the bars 52 of the main frame 8 and is pivoted thereto by a pivot pin 26. This pivot pin 25 extends through one pair of aligned holes 2? in the bars l2 of the main frame and a hole 28 in the stop block 24. The pair of holes 21 are spaced longitudinally in the bars I2 of the main frame 8 whereby the stop block 24 may be adjusted toward or from the pivot pin If! to engage the flanges of angle bars I2 of different thicknesses and radius blocks having different radii.

The bending block 25 is interposed between the bars 13 of the swinging frame 9 and pivoted thereto by a pivot pin 29. This pivot pin 29 extends through one pair of aligned holes 36 in said bars and a hole 3! in the bending block 25. Said holes 33 are spaced longitudinally from the pivot pin it to permit adjustment of the bending block 25 relative to the radius blocks l9.

The stop block 24 and the bending block 25 are identical, the one with the other. Figs. 4, 5, 6 and 7 illustrate the bending block 25 and will now be described in detail. This bending block 25 includes a body member 32 having a. face plate 33 provided with inturned flanges 34 which embrace the body member 32. The lower edges of the flanges 34 are upwardly and rearwardly inclined to afford wedge-acting surfaces 35 which rest on correspondingly formed shoulders 33 on the side of the body member 32. These shoulders 38 support the face plate 33 for compound vertical and horizontal movements relative to the body member 32. Coiled springs 33' anchored to the body member 32 and attached to the face plate 33 yieldingly hold said face plate with its flanges 34 on the shoulders 35. On the face of the bending block 25 is an upper horizontally disposed retaining shoulder 38 integral with the face plate 31, and integral with the body member 32 is a lower retaining shoulder 33 which is parallel to the shoulder 38. These shoulders 38 and 33 are vertically spaced to receive therebetween the vertical flanges of the two angle bars m and hold said flanges against separation during bending thereof. The face plate 33 between the shoulders 38 and 39 is concave in horizontal cross-section, as indicated by the numeral 40, so that the contacting angle bars a: have a two-point contact 4| therewith.

It is well known that the flanges of angle bars of a given width often vary slightly either way from the intended width. The purpose of providing the bending block 25 with a movable face plate 33 is to provide for the self-adjustment of the retaining shoulder 38 relative to the retaining shoulder 39 to engage the outer longitudinal edges of the vertical flanges of the angle bars :c. The normal distance between the retaining shoulders 38 and 39, when the: bending block 35 is applied to a pair of angle bars, is such that the face plate 33 is spaced slightly from the body member 32. When pressure is applied to the bending block 25 by the swinging frame 9, to bend the angle bars .7: around the radius blocks ill, the wedge-acting surfaces 35 on the inclined shoulders 35 tend to move the face plate 33 downwardly and thereby clamp the vertical flanges of the angle bars at between the shoulders 38 and 39 and also positively hold the horizontal flanges of said angle bars clamped the one upon the other.

The function of the stop block 24 is the same as that of the bending block 25 except that the angle bars a: during bending thereof, apply the force thereto that tends to move the retaining shoulder 39 toward the retaining shoulder 38 and thereby clamps the vertical flanges of the angle bars at therebetween and holds the two angle bars x the one upon the other and prevents separation thereof during bending. The parts of the stop block 24 shown and that correspond to like parts of the bending block 25 are given the same reference numerals followed by a To simultaneously bend the pairs of angle bars .22, they are placed, the one upon the other, with their horizontal flanges between the radius blocks 9 and their vertical flanges, at one of their end portions, between the bending surfaces 23 of the radius blocks I9 and the stop block 24. The swinging frame 9 is first moved to closely position the bending block 25 to the stop block 24 and with the vertical flanges of the angle bars a: between the retaining shoulders 38 and 39 of said bending block. With the angle bars it thus mounted in the bending machine, the swinging frame 9 is pulled away from the fixed main frame 8 by the hand lever It. This movement of the swinging frame 9 slides the bending block 25 on the vertical flanges of the angle bars a: and thereby bends said bars on the bending surfaces 23 of the radius blocks Hi. This operation forms a relatively short bend in the angle bars a: on the arc of a circle of a predetermined radius. The swinging frame 9 is again moved toward the main frame 8 and the angle bars fed endwise toward said main frame and between the radius blocks l0 and the stop block 24. Next, the swinging frame 9 is again pulled away from the main frame 8 to further bend the angle bars m. The above described operations are repeated until a complete circle has been formed or any part thereof.

From the above description, it is evident that with the horizontal flanges of the angle-bars :1: held the one upon the other between the radius blocks l9 and with the vertical flanges of said angle bars clamped between the retaining shoulders of the stop block 24 and the bending block 25, the bending of the angle bars a: will generate opposing pressures that will counteract the stresses that tend to twist the opposing horizontal flanges of said bars toward each other so that the angle bars at will retain their normal angle shape. Angle bars simultaneously bent in pairs as above described will remain in perfect planes without distorting their right angle shape.

While the invention is shown and described as a hand-operated bender, it is evident that the same may be embodied in a bulldozer.

It will be understood that the invention described is capable of various modifications within the scope of the invention herein disclosed and claimed.

What I claim is:

1. In a device of the class described, a pair of opposing members having bending surfaces for holding two of the flanges of a pair of angle bars therebetween and with their other flanges in opposing relation to the bending surfaces, means for bending the angle bars on the bending surfaces, and a block comprising a pivoted body member and a face plate having side flanges embracing the body member and holding said face plate for compound movement towardthe body member and relative endwise movement, a pair of opposing shoulders, one of which is on the body member and the other on the face plate engaging the longitudinal edges of the flanges opposing the bending surfaces, co-operating wedge-acting surfaces between the body member and the side flanges, constructed and arranged to impart said compound movement to the face plate when said face plate is subjected to pressure generated by bending the angle bars and thereby press the angle bars toward the bending surfaces and draw the shoulder on the face plate toward the shoulder on the body member and clamp the respective flanges between said shoulders.

2. In a device of the class described, a frame, a clamp on the frame for holding two of the flanges of a pair of angle bars, the one upon the other, and having a bending surface with which the other flanges of the angle bars are in opposing relation, lever-actuated means for bending the angle bars on the bending surface including a bending block having a pair of clamping members for holding the unbent portions of the angle bars against separation in the plane thereof during bending of the angle bars. said clamping members having cam surfaces that impart operative movement to the clamping members when they are subjected to pressure generated by bending the angle bars which exerts a force that tends to spring the angle bars apart and release the clamping members.

3. In a device of the class described, a frame, a clamp on the frame for holding two of the flanges of a pair of angle bars, the one upon the other, and having a bending surface with which the other flanges of the angle bars are in opposing relation, means for bending the angle bars on the bending surface, and, a stop block on the frame comprising a pair of clamping members for holding the portions of the angle bars against separation in the plane thereof during bending of the angle bars, said clamping members having cam surfaces that impart operative movement to the clamping members when they are subjected to pressure generated by bending the angle bars, Which exerts a force that tends to spring the angle bars apart.

4. In a device of the class described, a frame, a clamp on the frame for holding two of the flanges of a pair of angle bars, the one upon the other, and having a bending surface with which the other flanges of the angle bars are in opposing relation, means for bending the angle bars on the bending surface, a stop block and a bending block, each comprising a pair of clamping members, said stop block being on the frame and the bending block being a part of the bending means, said two blocks holding, respectively, the bent and unbent portions of the angle bars against separation in the plane thereof during bending of the angle bars, the clamping members of each pair having cam surfaces that impart operative movement to the clampin members when they are subjected to pressure generated by bending the angle bars which exert a force that tends to spring the angle bars apart.

5. The structure defined in claim 2 in which the clamping members are self-adjusting.

6. The structure defined in claim 3 in which the clamping members are self-adjusting.

7. In a device of the class described, a frame,

a clamp on the frame for holding two of the flanges of a pair of angle bars, the one upon the other, and having a bending surface with which the other flanges of the angle bars are in opposing relation, and means for bending angle bars on the bending surface including a bending block, comprising a pair of clamping members slidably connected and, having opposing abutments engaging the outer longitudinal edges of the flanges in opposing relation for holding the unbent portions of the angle bars against separation in the plane thereof during bending of the angle bars, said clamping members having cam surfaces that impart operative movement to the clamping members when their abutments are subjected to pressure generated by bending the angle bars which exerts a force that tends to spring the angl bars apart. a

8. In a device of the class described, a frame, a clamp on the frame for holding two of the flanges of a pair of angle bars, the one upon the other, and having a bending surface with which 7 the other flanges of the angle bar are in opposing relation, means for bending the angle bar on the bending surface, and a stop block on the frame comprising a pair of clamping members slidably connected and having opposing abutments engaging the outer longitudinal edges of the flanges in opposing relation for holding the bent portions of the angle bars against separation in the plane thereof during bending of the angle bars, said clamping members having cam surfaces that impart operative movement to the clamping members when their abutments are subjected to pressure generated by bending the angle bars which exerts a force that tends to spring the angle bars apart.

ALBERT HOSSFELD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 758,897 Budd May 3, 1904 1,832,210 Hossfeld Nov. 17, 1931 1,346,957 Hansen July 20, 1920 1,823,047 Hothersall Sept. 15, 1931 1,153,663 Wiedeke Sept. 14, 1915 366,880 Rix July 19, 1887 1,263,301 Wheeler Apr. 16, 1918 1,351,472 Farmer Aug. 31, 1920 

